Equipment for treating teeth by means of finely powdered materials carried by a stream of gas



Dec. 8, 1953 R. c. ANGELL 2,661,537

EQUIPMENT FOR TREATING TEETH BY MEANS OF FINELY POWDERED MATERIALS CARRIED BY A STREAM OF GAS Filed Feb. 15, 1950 Patented Dec. 8, 1953 EQUIPMENT FOR TREATING TEETH BY MEANS OF FINELY POWDERED MATE- RIALS CARRIED BY A STREAM OF GAS Robert 0. Angel], Prince Bay, N. Y., assignor to Robert B. Black, Corpus Christi, Tex.

Application February 15, 1950, Serial No. 144,324

This invention relates to the art of dentistry and is more particularly concerned with the provision of equipment for cutting, excavating, polishing or cleaning teeth by means of finely powdered materials carried by a stream of gas. In the following disclosure I will refer to all of these various operations broadly as treating procedures. A typical example is disclosed in the copending application of Robert B. Black, Serial No. 78,068, filed February 24, 1949, said Black being the assignee of the invention disclosed herein. In fact the vibrating equipment shown in the application referred to is particularly well adapted for use in and has been incorporated as a component part of the equipment claimed herein.

The principal objects of the invention are to provide equipment for treating teeth by means of finely powdered materials'carried by a stream of gas wherein immediate and prompt response to the needs of the operator is always insured; wherein any one of a plurality of powdered materials may be employed depending upon the nature of the treatment required; wherein the proper material for any given operation may be quickly and easily selected without the necessity for replacing any parts and without need for any particular adjustments in the equipment; wherein the equipment may be cleaned or purged of one type of powdered material before another is introduced; wherein the feed of one materialmay be positively and abruptly discontinued when another is required so as to avoid clogging of the lines; wherein means are provided for feeding the powdered material into the stream of gas, which means are under the primary control of the pressure in the gas line and are constructed and arranged to be inoperative unless a predetermined minimum pressure exists in said line; wherein a shut-oif valve is provided in the conduit which carries the stream of gas and powder to the nozzle which directs it against the tooth, which shut-01f valve is located in close proximity to the nozzle; wherein additional powdered material may be introduced into the apparatus in a simple and expeditious manner; and, in general, wherein the entire operation of treating teeth by one or another of several kinds of powdered materials is rendered simple, accurate, and definite to a very high degree and, further, wherein the apparatus employed is easily and highly maneuverable.

How the foregoing together with such other objects as may appear hereinafter or are incident to my invention are attained is illustrated, in a 11 Claims. (Cl. 3258) preferred embodiment, in the accomapnying 'drawing which discloses equipment suitable for accomplishing the purposes of the invention, the figure being largely diagramatic in its showing.

In the drawing the handpiece Ill is the part which the dentist holds in his hand in performing whatever treatment the patients teeth Inayrequire. Per se the details of this handpiece form no part of the invention claimed herein so they are not illustrated except that it should be noted that the mixed stream of gas and powdered material passes through the handpiece and is discharged or delivered through a very fine nozzle l l. The structure of this handpiece is preferably of the type illustrated in the copending applications of Dr. Robert B. Black, Serial Nos. 78,068 and 126,311 filed, respectively, on February 24, 1949, and November 9, 1949. v

The gas (preferably carbon dioxide) which fcarries the powdered material comes from any suitable source or reservoir as, for instance, the

high pressure tank or cylinder [2 and the gas reaches the handpiece and the nozzle through a suitable conduit I3 in which are included three separate paths of flow arranged in parallel and indicated generally in the drawings by the reference characters 13a, i312 and I30. These parallel paths of flow are connected to the main conduit [3 on the reservoir side of the equipment at the point hi and, on the handpiece side of the equipment, at the point 15. I

,A cylinder of carbon dioxide such as is suitable for the purposes of the present invention often carries a pressure in the neighborhood of 800 pounds per square inch at room temperature and this pressure is maintained as long as there is anyv liquid carbon dioxide left in the cylinder. This pressure, however, is too high for the purposes of my invention so I introduce a pressure regulator l5 at a point just beyond the cylinder shut-off valve ll. A gauge [8 for indicating the pressure may be connected to the pressure regula tor I5 if desired.v V

The pressures whichare most suitable for the operations to be performed by my equipment can vary over. a considerable range and, of course, the pressure at the nozzle I I isthe pressure which is important, For most operations I have found that this pressure should be in the neighborhood of eighty-five pounds. However, pressures as low as approximately thirty pounds at the nozzle and running all the way up to as high as approximately 200 pounds can be employed but it is' interesting to note in this connection that in the upper range, that is, above eighty-five pounds,

In connection with this matter of pressure wish to point out that, for obvious .reasons, it is impractical to apply a gauge .or :aregulator in the vicinity of the nozzle, say an lthe handpiece ID. In lieu of this the regulators IB and I9 are provided, but the pressures which-should be held by these regulators will depend, of cours'e, upon the drop in the line between the :regulators and the handpiece. A number of factors have a bearing upon this, such as the length -ofthe conduit and its diameter as well as the absorption in rthemixers and in dshepinchval-ves to headescribed :hereinafter. :For example, 'with certain equipment :which .-I have recently employed, 1 have :found that this drop in pressure between the regulators and the nozzle averages :thirtylafille 'toiorty pounds. Under :these conditions :it .is necessary to set the regulators accordingly in ,order to hold the desired'pressuresat the nozzle. For instance, for a pressure-of-eighty-fivepounds at the nozzle :the regulator 16 should *be set-at approximately 120 to 130 pounds. If a pressure as --low *as thirty'i-pounds at the nozzle isdesired, then, ofzcourse, the regulator 49 :should beset rat -firom si-xtyefive zto seventy-five pounds.

the .:lower maximum desirable, the

ya'lve' zu-may-be used torcloseitherlineila and open the Joy-pass :13 through .the regulator 19 which is set to give a pressure :of from sixty-five toseventry-five "pounds per @square inch. With ,just a :little'experience a-dentist can quickly determine =-what=pressmeat the regulator will-give the best results for .his vparticular equipment. .The above :figures aregiven merely as examples because the drop pressure may vary over quite :a wide range 'depending upon-the design of theiequip- .ment.

.The pinch valve :10, when :open, and :around which the by-gpass conduit .13 is extended, will permit the 120 to 130 pounds pressure looming ,f-rom the regulator 4.6 toipassthrough the conduit l3 to a pressure actuated controhswitch 2]. When the .valve zflris-aotuated to close theline t3, the gas will flow through the low :pressure regulator +9 which, in this :instance, I prefer to .adjust .to

SiXty-fiVe .to-seventy five pounds ,per suuareinch.

different tpowdered :materials :are generally all *7 that are required to accomplish most :of 'the operations necessary to adequately :take careof a pa'tientis teeth.

A cutting TDOWdBI is carried ainaa reservoir :01

mixer 22 fanii a.cleaningipowderzinzanother exacti ly similar mixer 23. However, since the mixers 22 and 23 are exactly the same, only one of them (23) with its associated equipment will be described in detail.

Each mixer consists essentially of a container having a hopper-like bottom portion 24 which delivers through a perforated-plate s25.-.into the mixing chamber proper 2-6,.the plate '25 being provided with a series of small apertures suitable for this purpose in the manner described more fully in the copending application of Dr. Black, Serial No. 78;068,;referred to above.

Qne side-ofthe passage I30 delivers the gas to 'the small mixing chamber 26 and the mixture of gas and powder isssubsequently conveyed through the dtherside of the passage I30 to the junction point 45. and .from .there to the handpiece ID in the manner already described. Both sides of :thespassage I30, 1. e., the side which leads to the mixing chamber 26 and the side which carries the mixture away :from [the c-chamber; 2Z6, are-.seither .closed :oruopened simultaneously .by .means pf :31

double armed pinch valve 2-?! which, is normally biased to the closedgposition hy.means-:of :the spring 28. In .the idrawing the two -=1SideS-:.0.f the massage L30 ..are closed [so .that norgaszcamreaeh .the mixing chamber .26. :In .-this.,-position .-.the

.microswitoh29 is open .sothat .no current scan new to the electromagnetic device .30.

The scontainer :23 :\i-s zmounted suponxthe tahle 3| which, in turn, list-supported .by the inclined legs '32. .The electromagnetic .-.deviee:.-3 l1, when zactuated, wibrates the table and with .it .the eontainerza This causes -.the, powder.-in {the icon- ;tainer23 toialidownthrough-the apertured plate 25 into the mixing chamber 26 where it is. -.picked up by the gas as it ztlows .-.thr.oug-h the passage J30. The operationwofta yibratornf this-type quite well ,knowninithe art,..-for -which..1=eason no .fuller description .is thought-to .be .necessary. alt might be noted, however, .that the '--details of the vibrating. .feeder mechanism which .-I .-haxe-.-.-.em ,ployed .are.more .more .iull yeset forth in the-.copendingapplication .of ...Rober.t.i3. ,Black, .Serial .NolIBDBB.

The container 423 is air-tight :and :is sealed .at .the top by-meansof-.alcovertorscap plate .3-3-which may he threaded or otherwisemseoured.againstla eooperatinggasketst. I-Ilie cover .may -be revmoved .wihen .-it.is-.desired to refill .the container .23 .and whenthis is done, .pressure :within the container .can be reduced to atmospheric .pres- .sureby opening the ,pinchvalve;3.5 whichrcontrols the bleed-riff =piP-e 35. Of .-course .the .closure leap .33. should. not .be removed .until :such time .-,as .the pinch valve .-2J..closes vthe -passage .1 3c.

lnerder ,to =equa1ize the pressure throughout .-.the c ontainer 23 .and .the mixing chamber vl6 .quickly .as possible, I :jprovide .the upwardly ex- .tendin'ghalancing tubes?! which projects :into-an enlarged .recessl38dn .the ,underiace of fth-etcap 33. .Theupper .end of the ,tube 3'! is preierably: closed as to=prevent .the powder. irom inadvertently iallingldowninto the-balancing tubeduringafilling operation. laterahopeningseflnear the. .top

of .thetube provide ior passageof the gas .from the interior of the .tube to the interior of the containcrata pointabovetherlevel .ofitheipowder. Lhe .area of the .balancing tube :is :made many .times that -.of the passage $30 -so :that the pressure {in the mixing chamber ?-26 and 'in ethe space in the container 23 above the powder is :at -.all times so :nearly equalized that the .rate of "feed- :ing -=the powder :intoathe nni-xing :zchamber is not The vibrating feeder mechanism so far described is duplicated exactly in connection with the mixing chamber 22 so that a description of the latter would be a mere duplication and; therefore, will not be undertaken. Sufiice it to say that I the corresponding parts associated with the container 22 have been given the same reference characters but with a prime mark added thereto.

The by-pass 53a is controlled by a pinch valve 40 which is biased to closed position by a spring 4|. By depressing the yoke 42 the pinch valve 40 may be opened.

The pinch valves 21, 2'! and 46 are controlled by means of a selector valve 43 having a cam surface 43 adapted to be rotated 50 as to engage one only of said pinch valves at a time. In the position shown in the drawing the cam 43 is shown in the position it occupies when it holds the valve 21' in its opened position, thus leaving the other two valves, namely, 21 and 40 in their closed positions. With the selector valve opening the pinch valve 2?, the micro switch 29' is closed so that current can flow to the electromagnetic device 30 which vibrates the table 3 l and the container 22 resting thereupon. Cutting powder will then' be fed into the mixing chamber (not shown but exactly like the chamber 26) where it will be picked up by the gas entering through the passage [3b to be carried to the handpiece I0.

At a point between the junction and the handpiece [0 I introduce another pinch valve 45 for controlling the passage through the conduit l3. This pinch valve should be located as close to the handpiece as is practical so as to reduce the length of conduit l3 which extends between the pinch valve 44 and the handpiece H) to as short a dimension as possible. This will reduce the amount of powder in the conduit l3 between 44 and H to the lowest possible figure when the pinch valve 44 is closed'so that, upon reopening the pinch valve, there will be no tendency to suddenly discharge a large quantity or slug of inert powder which would otherwise be present from the previous use of the equipment.

The pinch valve 44 is normally biased to closed position by the spring 45 and the valve is opened when the solenoid 46 is energized.

The equipment so far described is electrically actuated and controlled in the following way. Current is supplied throug the customary 110 v. A. C. line 61-48, there being a main switch 49 for closing and opening the circuit which leads to the equipment. When the proper pressure exists in the line I3, the switch 2 la will be closed whereupon current will reach the dentists foot switch 50 through the line lla when the main switch 59 is closed. After passing the foot switch the current reaches the solenoid '46 through the wire 5| and returns through the wire 38a to the main switch 49 and the supply line 47-48.

At the same time current can reach one or the other of the vibrators tildepending upon whether or not the selector control valve has opened pinch valve 21 or pinch valve 21'. In the illustration pinch valve 27' is open so current will flow through the wire 52 to the vibrator returning from the vibrator through the wire 53 and micro switch 29', the latter, of course, being closed when the valve 21' is open, as already described. Continuing with a description of the vibrating circuit, it will be seen that the current flows through wire 54 and wire 55 to the rheostat 56 and rectifier 51 and thence back to the main 48a through the wire 58.

If the selector control valve has been turned so 6 as to open the pinch valve 21, then the circuit is completed to the other vibrator 30 in the following way, the micro switch 29 being closed under this condition. Current flows through the wire 59 to the vibrator 30 and then through the wire 60 to the switch 29 and from the switch 29 through the wire 6| which meets the wire leading to the rheostat 56 and the rectifier 51, the circuit being completed as before through the wire 58 leading back to the main 48a.

A volt meter 62 is connected across the circuits for the vibrators by means of the wires 63 and 64 and the voltage across the vibrator circuits can be controlled by means of the rheostat 56.

The rectifier 57 provides a pulsating direct current to the vibrators at a frequency of 3600 per minute on cycle current and I have found it advisable to employ such a rectifier because without it the frequency (namely, 7200) would be too high for best operation in the feeding of the powder into the stream of gas.

By varying the voltage across the vibrators by means of the rheostat 56 it is possible to control the quantity or number of particles of the powder which is delivered to the gas in the manner more fully described in the copending application of Dr. Black Serial No. 78,068 referred to above.

In summary form the equipment is operated in the following manner. With the gas valve I! open so that pressure will be supplied to the systom the dentist will see that hand actuated pinch valve 29 is either open or closed in accordance with the maximum pressure which he expects to require for the dental treatment under consideration. With the valve 20 open the regulator 55 will be effective and, in accordance with the examples given earlier in this description, this is set to pass a pressure of from to pounds. If less pressure is desired, the valve 20 is closed whereupon the regulator I9 takes over and con trols the pressure to a maximum. of sixty-five to seventy-five pounds per square inch. In either event the pressure will then pass through the line I3 and will be sufficient to close the switch 21a so that the electric circuits will be activated when the foot switch 50 is closed. If for some reason or other the pressure is inadequate, the switch 2| a will remain open so that none of the electrical equipment can function with the exception of the exhaust mechanism which is connected across the line 65. This exhaust mechanism, however, is not illustrated or described because it forms no part of the present invention.

The dentist will also have to select the type of powder with which he wishes to work and this is done by turning the selector control valve 43 so as to open one or the other of the pinch valves 21 and 21. If a cutting operation is to be performed the valve 21' is opened by moving the cam 43 into the position shown in the drawing. At the same time the switch 29 is closed so that the current can reach the vibrator 33' whereupon the powder in the mixer 22 will be fed into the line l3b.

coincidentally with the foregoing, the pinch valve 54 will be opened so that the mixture of gas and powder can be delivered to the handpiece l8 and ultimately to the nozzle I I which directs the stream against the tooth.

By opening and closing the foot'switch 55 the dentist can easily and positively control the operation of the cutting stream-starting or shutting it off substantially instantly which is a very casein #53 7 7 r iimll liiant point .in prop fun tio in o the system. The "valve 44, as indicated :above, q placedw-as close .to the lhandpiece l-JJ ;as is prac- :tlCBiLSOaStOJGdVE alength of conduit H 3 between the valve 44 and the handpiece 1.0 which is as rshort as possible. In this way thereis never an -.=accum ulation of any large -:qua-ntity of inert gnowder such 'as would otherwise occur this :length of conduit were unduly extended.

If the work being doneby the dentist requires ;moreor less of the cutting powder he can regulate the quantity which is fed to the'st-ream of gas by -means of "the -rheostat 5.6. The higher the voltage delivered to the vibrator, theg'reater 'will-be theamplitude of vibration and the'greater will be the quantity of material fed :into the stream of gas.

If cleaning powder is desired 'for the work in handytheselector control valve gisturned so as to .lopen the pinch valve 21 whereupon :exactly the same type of operation will take place-in con- :nection with the vibrator 30 as has "just been described in connection with the vibrator 30'. ,However, before switching from the cutting pow- ..der to the cleaning powder, it is necessary to 50183.1 theline between the junction point !:5 and :the ,handpiece m of any of the cutting material and this is done by turning the selector control valve so as to :openthe pinch valve 470. This .per-

mits free gas .to pass through the line 13a and :thence to the nozzle I'l, thus blowing out any of thegcuttingpowder which may lie in the line 13 between the junction I5 "and the nozzle M.

,It will be appreciated, of course, that the selectorcontrol valve .43 can open only'one of the .pinch valves 2'1, 21 andMLat atime and further that when any one of these threeis open, .the other two are always closed. This-prevents any .;possibility of powder from the wrong container ,fiowing to the nozzle ,1] andiin this connection it is important that both :sides of the conduit leading to each of the powder containers should be closed when-such container is not use and also that the vibrator forsuch container .should .be inactivated when its powder is not required.

,All of this is provided ,for by myequipment as already described.

The pinch valves illustrated, especially :where the cutting powder is involved, :are very important in .the equipment Ihave devised .zbecause L more successfully than is possible 'yvith any lmetallic valve.

:Iclaim:

;1. Equipment for treating teeth :by means .of finelypowdered materials carried by a streamof gas, comprising, in combination with a source -of compressed gas, a-nozzle, conduit means connecting the gas source with the nozzle, at least two containers for holding powdered treating :material, means for delivering material from each container into said conduit means, said material delivery means including a normally inactive vibrator for each container, a valve nor- :mally closing the conduit means on the nozzle :side of the delivery means, means for conditioning one vibrator at a time for activation, and means for opening the conduit-valve and simultaneously effecting activation of-the conditioned vibrator.

. 2. Equipment according to claim 1 having in addition, a conduit for by-passing :gas around :said zdelivery means swithzaqcontrol valve ithere- :ior whereby ,to clear lone powder irom the nozzle before another is introduced.

3. Equipment for treating iteeth .by means of finely powdered materials-carried by .a stream 01 gas, comprising, in -,combination with a 'source- .of compressed. gas, a-nozzle, apluralityof containers for powdered materials, conduit means including passages .in arallel ;for connecting the gas. source with the nozzle,,a;parallel passagebeing prtovided for each [material .and one as a .free gas line, means for delivering material ,irom-each .container:intoitsrespective passaeaa ,valve for-controlling .each parallel ipassage, :a valve normafly closing the -,conduit means -onthe nozzle zside of :the delivery means, uneans for opening only one of the passage valves at-a :time, and means .for opening the said-conduit valve.

4. Equipment according to claim .3 ,havingrin :addition means for vibrating -,each. container.ol 1y attimes when the valveiin its associated parallel passage :is open.

.5. Equipment accordin .to .claim ..3 having ,in .addition.electro-rnagneticallyactuated.meansfor vibrating .each container, a. switchgior controlling the current for said .eleotroemagnetically ,actuated vibrating means. and ,meansadapted .toolose said switch when "the .pressure .in the conduit means exceeds a ;predetermined standard.

- 6. Equipment .for treating .teeth vbyzneans of finely powderedlmaterialsvcarried by a,. streamof zgas,.comprising, in. combination Witha source of compressed gas, a nozzlea container for tooth cutting powder, a second container ,ior tooth cleaning powden-conduit means having .two passages in .parallel for lconnecting the gas .source wi h t no l one .of said ,parallel assages being arranged-to pass through the cutting pow- .der container ,and. theother through the clean- ,ing powder container, whereby :the respective powdersmay ,be entrained by the gas, valve ,means for ,each i arallel passage constructed and arranged to control thepassage on .bothisi'des .of the container, ,a .valve normallyrclosing thereon- .duit on zthenozzleside of the parallel passages,

means for .opening'only. oneof theapassage valves at a time, and means .for opening thesaidcon- .duit valve.

.7. v,Iilquipmentaccording to .claim .6 having in addition, ,a conduit :for .by-passing gas .around said ;parallel,passages anda Nalve for controlling :the same whereby one powder may be cleared .from the ,nozzle before the other .is introduced.

8..Equipment according toclaim ,6 having in .addition .means :for vibratingeach ,containeronly at times when the valve in its associated parallel passage is open.

-,t-hepowder qdeliverymeansincludes a vihratortfor the container :theoperation of which js,.discontinued when :said valve means sis closed.

11. Equipment iorztreating'teeth by meanswof finely powdered materials carriedibysa streamrof gas, comprising, in 'eombinationwithaa source of compressed gas, a nozzle, a conduit connecting References Cited in the file of this patent the gas source with the nozzle, a container for UNITED STATES PATENTS holding powdered material, means for delivering material from th container into said conduit, Number Name Date said delivery means including electro-magneti- 5 11664369 Maurer Man 1928 cally actuated means for vibrating the container, 1,390,164 Rosenberger 6, 1932 a switch for controlling the current for said 1953091 Westberg et a1 APR 3, 1934 electro-magnetically actuated vibrating means, FOREIGN PATENTS and means adapted to close said switch when Number Country Date the pressure in the conduit exceeds a predeter- 10 525,444 France June 6, 1921 mined standard.

ROBERT C. ANGELL. 

